#include<cstdio>

int main() {
    int a, sum = 0;
    double b, avg;
    scanf("%d", &a);
    for (int i = 0; i<a; i++) {
        scanf("%lf", &b);
        sum += b;
    }
    avg = sum * 1.0 / a;
    printf("%.2f", avg);
    return 0;
}